A composite application is a software application that is constructed by combining multiple existing functions into a new application. A composite application can use business sources, such as existing software components or modules, as well as information services, including business services and/or Internet web services. Such services may be provided in the context of a service-oriented architecture (SOA) for instance. Services expose application programming interfaces (APIs), which are also referred to as contracts, and which define how consumers—i.e., applications—can interact with the services. A composite application can incorporate the orchestration of its various constituent parts via internal logic that dictates how the functionality provided by these parts interact to generate new, derived functionality. By using existing services, components, and modules, a developer thus may be able to develop a composite application in less time than coding an application from scratch. Development and testing of a composite application is typically performed against the resources that the services provide, such as their contracts (e.g., APIs).